Hydrogen electrode reaction: a complete kinetic description

P. M QUAINO; M. R. GENNERO DE CHIALVO; A. C. CHIALVO

ELECTROCHIMICA ACTA

Elsevier

Lugar: Ireland; Año: 2007 vol. 52 p. 7396 - 7403

0013-4686

The kinetic description of the hydrogen electrode reaction (HER) in the whole range of overpotentials (−0.2 < η (V) < 0.40) is presented. TheVolmer?Heyrovsky?Tafel mechanism was solved considering simultaneously the following items: (i) the diffusional contribution of the molecularhydrogen from and towards the electrode surface, (ii) the forward and backward reaction rates of each elementary step and (iii) a Frumkin typeadsorption for the reaction intermediate. In order to verify the descriptive capability of the kinetic expressions derived, an experimental study of theHER was carried out on a rotating platinum disc electrode in acid solution. From the correlation of these results the elementary kinetic parameterswere evaluated and several aspects related to the kinetic mechanism were discussed. Finally, the use of these kinetic expressions to interpret resultsobtained on microelectrodes is also analysed.